Pavement constructing



Jan. '26, 1937. v POULSON 2,068,702

PAVEMENT CONS TRUCTING Filed March 25, 1933 5 Sheets-Sheet l W I NVENTOR.

Vo/ney A. Pou/son.

L v mi k' ATTORNEKS.

1937. v. A. PouLsoN PAVEMENT CONSTRUCTING Filed March 25, 1933 5 Sheets-Sheet 3 INVENTOR. Vo/ney A. Pou/som.

ATTORNEYS.

Jan. 26, 1937 v A POULSON 2,068,702

PAVEMENT CONS TRUCT NG Filed March 25, 1933 5 Sheets-Sheet 4 v f I J g. a

INVENTOR.

Vo/neg A. Pou/son.

BY 57% W ATTORNEYX 5 Sheets-Sheet 5 1N VEN TOR.

ATTORNEY. S.

Vo/neg A. Pou/son. BY w 47 1937- v. A. POULSON PAVEMENT CQNSTRUCTING Filed March 25, 1935 Q Q 3 9 E a N\ W mm NM 3% mm NM MM MM FOOvfiOObfiOOwfiuObOOOO00000000000000 O m a U o @w m as a oooo@ ono@ ooooooeooo 9 2 Wm NM mum Mm Patented Jan. 26, 1937 UNITED STATES PATENT OFFICE Application March 25,

6 Claims.

This invention relates to pavement constructing and has for its object an apparatus for and method of quickly, efiiciently and economically laying pavement to obtain uniform distribution of material and uniform compression throughout the finished pavement.

According to the invention, the pavement is constructed by depositing, spreading, leveling and compacting a plurality of layers of pavementforming material during a single passage of the pavement-laying machine. Each layer is laid individually and is individually compacted by suitable compression means, thereby insuring uniform distribution of the paving material and uniform compression throughout the full depth of the pavement. Where a road is being resurfaced and is rough and uneven, the low spots are first filled and the filling compressed, after which the upper layers are laid on the smooth surface thus obtained, such layers being individually spread and compressed.

The individual layers may be laid as thin or as thick as desired, thereby minimizing to any degree desired, the occurrence of dense spots in the pavement and insuring uniformity of distribution. In depositing the layers of any one passage of the machine, the process is so nearly instantaneous that it prevents any tendency to produce a liminated pavement with a resulting tendency toward weakness or lack of cohesion between the separate layers, such as would be the case if any considerable interval of time and exposure should intervene between the laying of the separate layers.

A comparison of pavement laying according to the present invention with the present day operations of resurfacing an old pavement that has become rough and uneven will illustrate the superiority of the invention. At present, an old pavement that has been rendered rough and uneven through the ordinary wear and tear of trafiic is usually resurfaced by shoveling paving material into the road and spreading the paving material after which it is leveled by hand rakes and compacted by a road roller or in some instances by hand tamping. These operations are performed by laborers and depending upon the skill of the laborers this method may or may not produce a finished surface that is smooth and true to grade. Even when it appears that these conditions have been obtained they are seldom retained very long under trailic. The reason for this lies in the fact that instead of uniform distribution, it usually happens that the loose material is inadvertently accumulated into areas of differing density or 1933, Serial No. 662,716

may lie in the fact that the layer of loose material was of varying thickness due to the uneven surface of the old pavement. In either case, when the road roller is run over the loose material thus deposited, the weight of the roller is carried primarily by the spots of greater density and/or lesser thickness. Thus, there is a correspondingly uneven distribution of pressure from the roller and a correspondingly uneven distribution of compression in the pavement. This leaves soft spots in the pavement not readily detectable at the time the pavement is laid, but which are subsequently developed by traflic into low spots. Resurfacing a worn pavement according to the present invention consists in first filling the low spots up to a level lying at a predetermined distance below the level of the desired finished surface and compacting the same, laying a second layer up to a second level along a second predetermined distance below the level of the desired finished surface and compacting the second layer and so on until all the layers have been laid. Each layer is individually spread and compacted so that substantially uniform distribution and compression is obtained throughout the pavement.

A machine for laying pavement according to the invention comprises essentially a plurality of. chutes for delivering paving material to the surface to be paved in combination with a set of sclraping blades individual to each chute for spreading and leveling the paving material, the successive sets of blades being arranged at progressively higher levels. Behind each set of blades is provided a set of rollers for individually compacting each layer before the following layer is spread. The chutes are kept filled with paving material through the medium of an endless conveyor. Preferably, the last two sets of rollers support the rear end of the machine, while the front end is supported by traction wheels.

Other objects, novel features and advantages of this invention will be apparent from the following specification and accompanying drawings, wherein:

Fig. l is a plan View of a machine for laying pavement according to the invention;

Fig. 2 is a side elevation of the machine;

Fig. 3 is a vertical section partially broken away, substantially on the line 3-3 of Fig. 1;

Fig. 4 is a fragmentary section on the line 4-4 of Fig. 3;

Fig. 5 is a fragmentary end view of Fig. 4;

Fig. 6 is an enlarged fragmentary section substantially on the line 66 of Fig. 2;

Fig. '7 is a fragmentary section substantially on the line '|-'l of Fig. 3;

Fig. 8 is an enlarged fragmentary section substantially on the line 8-8 of Fig. 3; and

Fig. 9 is an enlarged fragmentary view generally similar to Fig. 3;

The pavement laying machine comprises a body H] supported at its front end by wheels II and a motor I2 is provided for driving the wheels to move the machine. The rear end of the machine is supported by two sets of rollers l3 and M, the rollers 53 being mounted at the ends of arms i5 pivotally connected to cross beams of the body it and the rollers l4 being mounted at the ends of arms |6 pivotally to cross beams of the body l6. Each set of rollers consists of two rows, the rollers in the second row being arranged behind the spaces left between the two rollers of the first row. The arms I5 and I6 are connected in pairs by links l! with opposite ends of levers l8. pivoted at l9 to the opposite ends of levers 20 pivoted at 2| to opposite ends of levers 22 pivoted at 23 to opposite ends of a lever 24- pivoted at 25 to an open frame 26 extending transversely of the body l9. Fig. 6 shows approximately one-half the width of the body H3 and frame 26 and also one complete set of levers. The other half of the body and frame and the other set of levers is identical with the half shown. At each end of each frame 26 is provided a bracket 21. At each side of the body a bar 28 is supported at its ends by the brackets 27 through the medium of ball and socket joints and is provided intermediate its ends with a recess in which is seated a trunnion 29 also received in a recess in a bracket Illa carried by the body it. The linkage between the rollers and the body minimizes up and down movement of the rear end of the body upon up and down movement of the rollers 3 and I4 when passing over an irregular surface. The rear end of the body is thus maintained at substantially uniform level. A shield 65 encloses each bar 28 and its aescciated brackets Z'l.

Within the body ill there is provided a conveyor 35 which overlies a table 3| having its ends bent upwardly along the arc of a circle. The conveyor consists of two sets of sprocket wheels 32a over which are arranged two endless chains 32 to which are pivotally attached buckets 33 provided with rollers 3'3 arranged in guide grooves 35. The buckets are of general U-shape in cross-section with one leg of different length than the other. The longer leg is pivotally attached to the chain 32 while the shorter leg carries the rollers 34. The buckets are slotted as at 33 to receive the chains 32. A plurality of chutes 36, 37, 38 and 33 extending transversely of the body l0, lead downwardly from the table 3|. Loose paving material is supplied to the buckets 33 and discharged by the buckets on to the front end of the table 3| and moved across the table by the longer legs of the buckets, the material dropping into the various chutes to keep the same filled up and any excess material is picked up by the buckets at the rear end of the table and carried again to the front end of the table.

Directly in back of each chute is arranged a transverse row of scraping blades, the blades in the various rows being designated 49, 4|, 42 and 53. Links 44, i5, 45 and 4'1 are pivotally connected to cross beams of the body It at one end and are rigidly connected to the scraping blades at the other end. A bar 48 extends transversely of the body behind the row of blades 40 and is engaged by arms 40a of the blades 40, this bar serving to limit the downward movement of the blades 46. Similar bars 49, 5D and 5| are provided for the remaining rows of scraper blades and are engaged respectively by the arms 4|a, 42a and 43a. The ends of the bars 48 to 5| are arranged in vertical guide members 48a, to Ella and are adjustably mounted in such members by pins 48b to 5|b. The various scraper blade arms are provided with guide pins 52 which are arranged in arcuate guide members 53 depending from the table 3|, these guide members serving to facilitate up and down movement of the scraping blades. A set of two rows of rollers 52 is arranged behind the first row of scraper blades, the rollers being attached to the free ends of arms 53 pivotally attached to a cross beam of the body iii. A second set of two rows of rollers 54 is arranged behind the second row of scraper blades, the rollers being attached to the free ends of arms 55 pivotally attached to a cross beam of the body Hi.

In conditioning the machine for operation, the cross bars 48, 49, 55 and 5| are adjusted at progressively higher elevations from the front to the rear of the machine so that the bottom edges of the blades 40 normally are at a lower level than the bottom edges of the blades 4| and so on with respect to blades 42 and 43. Paving material is supplied to the conveyor as will be subsequently described in detail and the conveyor is operated to move the paving material over the table 3|. Paving material will drop through the chutes 36, 3?, 38 and 39 and as the machine is advanced, each row of scraper blades spread and level the paving material banked up in front of it.

All depressions below the level of the bottom edge of the row of blades 4|] will be filled up to the normal level of the bottom edge of the blades 48 by paving material delivered through the chute 36 and the material thus deposited will be compacted by the rollers 52. Paving material supplied through the chute 37 will be, spread over the first layer up to the normal level of the bot tom edges of the scraper blades 4| by means of these blades and will be immediatelycompacted through the medium of the rollers 54. Likewise, additional layers of paving material will be spread and levelled and compacted by operation of the remaining chutes, scraper blades and rollers. Paving material supplied through the chutes 35 will be used only to fill up depressions up to the normal level of the bottom edge of the row of scraper blades as the scraper will drag the paving material over surfaces higher than the normal level of its bottom edge.v Paving material from the chute 31 will be used only to increase the pavement up to the normal level of the bottom edge of the scraper blades 4| and so on with respect to the paving material delivered through the chutes 38 and 39. The paving material from the chute 36 may completely fill in all the depressions and provide a smooth surface or may fail completely to fill up the depressions, in which event, the paving material, from a subsequent chute, will completely fill the holes and provide a smooth surface upon which the remaining layers are laid.

The cross bars 48, 49, 50 and 5| may be arched so that when arranged as shown in Fig. 7, the scraper blades are so arranged as to produce a crown centrally of the pavement and when arranged reversely, the scraper blades are arranged to produce a central depression. Also, the bars 43 and 5| may have straight surfaces so that they may be set to arrange the bottom edge of the blades horizontal or inclined, along a straight line. The cross bars may be provided at their ends with wheels 56 adapted to run on tracks to determine the elevation of the scraper blades. In this event, the bars will be mounted in the guide members 48a. to a, on the body for vertical movement.

The body Ill is provided with tracks 56a by which a cart or the like may be run up onto the body portion over the conveyor for the purpose of supplying paving material to the conveyor through an aperture normally closed by the cover 68. A winch 51, together with a cable 58 and a truck 59 provides means for drawing the cart BE! up onto the body Ill against stops arranged ahead of the cover 66. Paving material is discharged from the cart through an opening 6| in the top of the body l0 into the buckets 33 by which the paving material is distributed to the chutes. On the upper reach of the conveyor the buckets act as receptacles but on the lower reach the high sides act as spreaders. The buckets are so guided around the sprockets by the rollers 34 in the grooves 35 as to keep the edges of the sides in contact with the arcuate parts of the table. The buckets pick up the leftover paving material at the rear of the table and carry it to the front end.

An engine 62 is provided at the rear of the body together with gearing 63 between it and the rear set of sprocket wheels 32a for driving the conveyor.

An operators station 64 is provided at the rear end of the body and controls are provided within easy reach of the operator for applying power from the engines to the conveyor, winch and driving wheels. Also, a steering wheel may be provided for guiding the machine.

I claim:

1. In a device of the character described, a body, a plurality of transverse chutes serially arranged longitudinally thereof, a leveling unit supported by said body behind each chute, said leveling units being supported at progressively higher levels, a set of rollers arranged behind each leveling unit, equalizing linkage connecting the rollers of the last two sets to the rear end of said body for supporting the latter by the former, and wheels supporting the front end of the body.

2. In a device of the character described, a body, a table supported by said body, a conveyor arranged above said table and adapted to spread paving material thereover, a plurality of transverse chutes extending downwardly from said table and being serially arranged longitudinally of said body, a leveling unit arranged behind each chute, means for supporting said leveling units at progressively higher levels, a set of rollers arranged behind each leveling unit, equalizing linkage connecting the rollers of the last two sets to the rear of said body for supporting the latter by the former, and wheels supporting the front end of the body.

3. In a device of the character described, a body, wheels supporting the front end of the body, two sets of rollers at the rear end of said body, a frame at the rear of the body extending transversely thereof, arms pivoted to the body and attached at their free ends to the levers pivotally carried by said frame, and a succession of levers pivotally connected to said two levers, each lever being centrally connected to the end of the preceding lever, and links connecting the ends of the last levers with said arms.

4. In a device of the character described, a body, a plurality of transverse chutes serially arranged longitudinally of said body, leveling means arranged behind each chute, each leveling means consisting of a set of narrow blades alined transversely of said body, arms extending from said blades and pivotally connected to said body, bars extending transversely of said body, each bar being individual to one set of blades, members projecting from said blades and resting on said bars, said bars being arranged to support said sets of blades at progressively higher levels, and a compression member individual to each leveling blade arranged behind the same.

5. The method of constructing pavement on an uneven base which comprises laying in each depression of greater than a given depth, sufficient paving material to establish in each depression a predetermined level below the top level of the base, superposing additional layers of paving material of predetermined thickness and individually compacting each layer prior to laying the next layer upon it.

6. The method of constructing pavement on an uneven base which comprises in successive operations, laying paving material in the depressions in the base up to successive predetermined levels below the base top level, finally laying paving material up to a level above the top level of the base, and individually compacting each layer prior to laying the next layer upon it.

VOLNEY A. POULSON. 

